Symbiosis-related plant genes modulate molecular responses in an arbuscular mycorrhizal fungus during early root interactions

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Signposting compatibility events driving the mycorrhizal route

International audience

Developmental regulation of fungal-plant cross talk in arbuscular mycorrhiza

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Changes in polypeptide profiles of two pea genotypes inoculated with the arbuscular mycorrhizal fungus Glomus mosseae

The symbiotic interaction between pea roots ('Pisum sativum' L.) and the endomycorrhizal fungus 'Glomus mosseae' should lead to specific gene expression of both symbionts. In order to detect symbiosis-related proteins (endomycorrhizins), we used two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) after phenolic extraction of total soluble proteins. Furthermore, to better characterize the molecular changes after fungal infection, two pea genotypes available in our laboratory were used: cv. Frisson (myc⁺) and an isogenic mycorrhiza-resistant mutant (myc⁻). The latter prevents intraradical fungal development. Several differences were observed in polypeptide patterns of silver-stained …

Genetic variability in tolerance to cadmium and accumulation of heavy metals in pea (Pisum sativum L.)

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Mtha1, a Plasma Membrane H+-ATPase Gene fromMedicago truncatula,Shows Arbuscule-Specific Induced Expression in Mycorrhizal Tissue

: Transport processes between plant and fungal cells are key elements in arbuscular mycorrhiza (AM), where H+-ATPases are considered to be involved in active uptake of nutrients from the symbiotic interface. Genes encoding H+-ATPases were identified in the genome of Medicago truncatula and three cDNA fragments of the H+-ATPase gene family (Mtha1 - 3) were obtained by RT-PCR using RNA from M. truncatula mycorrhizal roots as template. While Mtha2 and Mtha3 appeared to be constitutively expressed in roots and unaffected by AM development, transcripts of Mtha1 could only be detected in AM tissues and not in controls. Further analyses by RT-PCR revealed that Mtha1 transcripts are not detectable …

Des facteurs de transcription fongiques impliqués dans l’établissement de la symbiose mycorhizienne à arbuscules

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Construction and validation of cDNA-based Mt6k-RIT macro- and microarrays to explore root endosymbioses in the model legume Medicago truncatula

To construct macro- and microarray tools suitable for expression profiling in root endosymbioses of the model legume Medicago truncatula, we PCR-amplified a total of 6048 cDNA probes representing genes expressed in uninfected roots, mycorrhizal roots and young root nodules [Nucleic Acids Res. 30 (2002) 5579]. Including additional probes for either tissue-specific or constitutively expressed control genes, 5651 successfully amplified gene-specific probes were used to grid macro- and to spot microarrays designated Mt6k-RIT (M. truncatula 6k root interaction transcriptome). Subsequent to a technical validation of microarray printing, we performed two pilot expression profiling experiments usin…

Developmental-regulated plant and fungal gene expression in mycorrhizal interactions with compatible and incompatible Medicago truncatula genotypes

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Mitochondrial genotyping of isolates of the arbuscular mycorrhizal fungus "Glomus intraradices" from the isolate collection of the International Bank of Glomeromycota

International audience; The culture collection of the International Bank of Glomeromycota (BEG) provides an important service to scientific community and industry by acting as a repository for well-defined AMF isolates which are made available to the public. The most widely-used species has been referred to as "Glomus intraradices", and was recently renamed Rhizophagus irregularis. This species has emerged as a model organism for experimental research and is the subject of the first AMF genome to be sequenced. The only genetic marker that can currently be used to distinguish strains of R. irregularis in field settings is the mitochondrial large subunit (mtLSU). In addition, genetically dist…

Monitoring AM fungi activity of pionnier plants colonizing spoil banks after brown-coal mining

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Mycorrhiza-induced resistance againsta root-rot pathogen in petunia: molecular mechanisms

Ribosomal sequences as a tool to study and monitor arbuscular mycorrhizal fungi

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Deciphering the molecular dialogue between arbuscular mycorrhizal partners during early root interactions

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Effect of 2,4-Diacetylphloroglucinol on Pithium : cellular responses and variation in sensitivity among propagules and species

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Dissection of Genetic Cell Programmes Driving Early Arbuscular Mycorrhiza Interactions

The persistence through evolution of the arbuscular mycorrhiza (AM) symbiosis between Glomeromycota and plants is probably due to a widespread molecular dialogue between the two partners. Most studies have focussed on established mycorrhizal systems whilst evidence for cellular commitment of the symbiotic partners during early developmental phases is recent. Whereas spore germination by AM fungi can occur spontaneously, subsequent hyphal branching, appressoria differentiation, root penetration and intraradical development leading to symbiosis establishment are under the control of molecular interactions between the two partners. In this chapter, recent work on AM fungus–plant interactions i…

Proteome analysis and identification of symbiosis-related proteins from Medicago truncatula Gaertn. by two-dimensional electrophoresis and mass spectrometry.

Time-course analysis of root protein profiles was studied by two-dimensional gel electrophoresis and silver staining in the model plant Medicago truncatula, inoculated either with the arbuscular mycorrhizal fungus Glomus mosseae or with the nitrogen fixing bacterium Sinorhizobium meliloti. Protein modifications in relation to the development of both symbioses included down- and upregulations, as well as newly induced polypeptides. Matrix assisted laser desorption/ionization-time of flight-mass spectrometry after trypsin digestion clearly identified one polypeptide induced in nodulated roots as a M. truncatula leghemoglobin. Internal sequencing with a quadrupole time-of-flight mass spectrome…

Local and systemic mycorrhiza-induced protection against the ectoparasitic nematode Xiphinema index involves priming of defence gene responses in grapevine

International audience; The ectoparasitic dagger nematode (Xiphinema index), vector of Grapevine fanleaf virus (GFLV), provokes gall formation and can cause severe damage to the root system of grapevines. Mycorrhiza formation by Glomus (syn. Rhizophagus) intraradices BEG141 reduced both gall formation on roots of the grapevine rootstock SO4 (Vitis berlandierixV. riparia) and nematode number in the surrounding soil. Suppressive effects increased with time and were greater when the nematode was post-inoculated rather than co-inoculated with the arbuscular mycorrhizal (AM) fungus. Using a split-root system, decreased X. index development was shown in mycorrhizal and non-mycorrhizal parts of my…

Plant gene responses to Glomus mosseae in compatible and incompatible genotypes of Medicago truncatula

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The contribution of model legumes to arbuscular mycorrhiza research

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Developmental-regulated gene expression in mycorrhizal interactions with host and non host Medicago truncatula

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Medicago truncatula gene responses specific to arbuscular mycorrhiza interactions

International audience

Expression communes de gènes de M. truncatula lors de la mycorhization, la nodulation et l'interaction avec une rhizobactérie bénéfique

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A β-1,3 Glucan Sulfate Induces Resistance in Grapevine against Plasmopara viticola Through Priming of Defense Responses, Including HR-like Cell Death

Sulfated laminarin (PS3) has been shown previously to be an elicitor of plant defense reactions in tobacco and Arabidopsis and to induce protection against tobacco mosaic virus. Here, we have demonstrated the efficiency of PS3 in protecting a susceptible grapevine cultivar (Vitis vinifera cv. Marselan) against downy mildew (Plasmopara viticola) under glasshouse conditions. This induced resistance was associated with potentiated H2O2 production at the infection sites, upregulation of defense-related genes, callose and phenol depositions, and hypersensitive response-like cell death. Interestingly, similar responses were observed following P. viticola inoculation in a tolerant grapevine hybri…

Common gene expression in Medicago truncatula roots in response to Pseudomonas fluorescens colonization, mycorrhiza development and nodulation

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Studies of root colonization by a microcosm community of arbuscular mycorrhizal fungi unsing nested PCR

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The role of the plant genome in modulating arbuscular mycorrhizal formation.

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Exploiting Glomus intraradices sequencing data to dissect molecular mechanisms of plant genome control over fungal gene expression in mycorrhiza

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Development and molecular biology of arbuscular mycorhizal fungi

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Molecular probes for studying population dynamics of arbuscular mycorrhizal fungi in roots and soil

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Variabilité entre 2 espèces de Glomus dans la survie de leurs propagules

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Bioalternatives to chemicals in plant production and in cleaning up the environment: hopes and reality

High-troughput TILLING to identify symbiosis-related plant gene function in arbuscular mycorrhiza

International audience

Role of a transcription factor, GintSTE, from Glomus intraradices in the establishment of arbuscular mycorrhizal

International audience

Localisation et visualisation de transcrits fongiques in situ: Une méthode originale qui combine biologie moléculaire et microscopie confocale

National audience; Les Gloméromycètes, formant la symbiose mycorhizienne à arbuscules, sont des champignons biotrophes obligatoires qui sont intimement associés aux tissus végétaux qu’ils colonisent. Les techniques utilisées pour suivre l’expression des gènes fongiques dans les racines mycorhizées ne permettent pas de définir le profil spatio-temporel de leur activité. Afin de tracer l’activité transcriptionnelle fongique dans les racines mycorhizées, une méthode innovante, basée sur la RT-PCR in situ, a donc été développée. Cette technique permet de localiser, en microscopie optique confocale à balayage laser, des transcrits fongiques, à l’aide d’amorces spécifiques marquées par un fluoroc…

Fungal proteins in the extra-radical phase of arbuscular mycorrhiza: a shotgun proteomic picture

International audience

Isolation and characterization of a BamHI element in psam3 a gene of Pisum sativum L. induced during early stages of arbuscular mycorrhiza development

Proteomics: a functional genomic approach for studying mycorrhizal interactions in legumes

Des bactéries intracellulaires dans le champignon ectomycorhizien Laccaria bicolor

National audience

A technical trick for studying proteomics in parallel to transcriptomics in symbiotic root-fungus interactions

We have developed a protocol in which proteins and mRNA can be analyzed from single root samples. This experimental design was validated in arbuscular mycorrhiza by comparing the proteins profiles obtained with those from a classical protein extraction process. It is a step forward to make simultaneous proteome and transcriptiome profiling possible.

Heavy metals in sewage sludges contribute to their adverse effects on the arbuscular mycorrhizal fungusGlomus mosseae

Applying sewage sludges to agricultural land is a widespread practice because of the sludges’ agronomic value as a source of plant nutrients and organic matter. Nevertheless, sludges often contain micropollutants that can constitute a menace for health and the environment. Arbuscular mycorrhizal fungi are sensitive to sewage sludges that have been spiked, or not, with metallic trace elements (MTE). Here we have investigated if MTE in sewage sludges could be responsible for effects on mycorrhizal development betweenGlomus mosseae andMedicago truncatula. The impact of a dehydrated or composted urban sewage sludge spiked or not with MTE, was tested on spore germination and root colonization by…

Localization of fungal gene expression at different stages of arbuscular mycorrhizal symbiosis : development of an in situ RT-PCR method

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Common plant genes and gene expression in arbuscular mycorrhiza and root nodule symbioses

International audience

Plant genes involved in arbuscular mycorrhiza formation and functioning

Knowledge about that part of the plant genome involved in the establishment and functioning of the arbuscular mycorrhizal (AM) symbiosis is important for the basic understanding of this symbiosis. It is also essential for a ‘genes to the field’ approach based on the identification and exploitation of genes that could be central to developing sustainable plant production systems in the future.

Glomalean spores and their DNA(s)

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Clonage d'un gène de champignon arbusculaire fonctionnel lors de l'endomycorhization

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Erratum to “Hydrolytic enzyme activity of Paenibacillus sp. strain B2 and effects of the antagonistic bacterium on cell integrity of two soil-borne pathogenic fungi”

Ce texte contient des corrections apportées à l'article " Hydrolytic enzyme activity of Paenibacillus sp. strain B2 and effects of the antagonistic bacterium on cell integrity of two soil-borne pathogenic fungi" sorti dans le numéro 15 du journal "Applied Soil Ecology" sorti en 2000.

Signal-related gene responses in beneficial root interactions with non-rhizobial microorganisms

International audience

Identification of arbuscular mycorrhizal fungi in soil and roots of plant colonizing zinc wastes in southern Poland

Genes encoding transcription factors in Glomus intraradices and their expression at the appressoria stage of arbuscular mycorrhiza interactions

International audience; Molecular pathways governing the life cycle of arbuscular mycorrhizal (AM) fungi and their symbiotic interactions with root tissues are not yet fully understood. Most studies fo fungal responses to host plants have targeted developmental stages before root contact (germinating spores), or after root colonization (intraradical mycelium). We are focusing on the early cell events of appressoria contact with the root surface which are essential to the successful outcome of the AM symbiosis. Recent monitoring of Glomus intraradices gene expression at this stage has revealed differential fungal responses to roots of host and non-host (Myc- mutants) M. truncatula (Seddas et…

Identification of mycorrhiza-regulated genes with arbuscule development-related expression profile

Suppressive subtractive hybridisation was applied to the analysis of late stage arbuscular mycorrhizal development in pea. 96 cDNA clones were amplified and 81, which carried fragments more than 200 nt in size, were sequence analysed. Among 67 unique fragments, 10 showed no homology and 10 were similar to sequences with unknown function. RNA accumulation of the corresponding 67 genes was analysed by hybridisation of macro-arrays. The cDNAs used as probes were derived from roots of wild type and late mutant pea genotypes, inoculated or not with the AM fungus Glomus mosseae. After calibration, a more than 2.5-fold mycorrhiza-induced RNA accumulation was detected in two independent experiments…

Symbiosis-related plant genes modulate molecular responses in an arbuscular mycorrhizal fungus during early root interactions: molecular in vitro and in situ approaches

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Symbiosis-related gene expression during early interactions between AM fungi and roots

International audience

Heavy metals in sewage sludges contribute to their adverse effects on the arbuscular mycorrhizal fungus Glomus mosseae

International audience

Symbiosis-related plant genes modulate molecular responses in an arbuscular mycorrhizal fungus during early root interactions.

To gain further insight into the role of the plant genome in arbuscular mycorrhiza (AM) establishment, we investigated whether symbiosis-related plant genes affect fungal gene expression in germinating spores and at the appressoria stage of root interactions. Glomus intraradices genes were identified in expressed sequence tag libraries of mycorrhizal Medicago truncatula roots by in silico expression analyses. Transcripts of a subset of genes, with predicted functions in transcription, protein synthesis, primary or secondary metabolism, or of unknown function, were monitored in spores and germinating spores and during interactions with roots of wild-type or mycorrhiza-defective (Myc–) mutan…

Influence of arbuscular and ericoïd mycorrhiza formation on level of photosynthetic pigments in host plants

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An STE12 gene identified in the mycorrhizal fungus Glomus intraradices restores infectivity of a hemibiotrophic plant pathogen

International audience; * • Mechanisms of root penetration by arbuscular mycorrhizal (AM) fungi are unknown and investigations are hampered by the lack of transformation systems for these unculturable obligate biotrophs. Early steps of host infection by hemibiotrophic fungal phytopathogens, sharing common features with those of AM fungal colonization, depend on the transcription factor STE12. * • Using degenerated primers and rapid amplification of cDNA ends, we isolated the full-length cDNA of an STE12-like gene, GintSTE, from Glomus intraradices and profiled GintSTE expression by real-time and in situ RT-PCR. GintSTE activity and function were investigated by heterologous complementation …

Genome of an arbuscular mycorrhizal fungus provides insight into the oldest plant symbiosis

International audience; The mutualistic symbiosis involving Glomeromycota, a distinctive phylum of early diverging Fungi, is widely hypothesized to have promoted the evolution of land plants during the middle Paleozoic. These arbuscular mycorrhizal fungi (AMF) perform vital functions in the phosphorus cycle that are fundamental to sustainable crop plant productivity. The unusual biological features of AMF have long fascinated evolutionary biologists. The coenocytic hyphae host a community of hundreds of nuclei and reproduce clonally through large multinucleated spores. It has been suggested that the AMF maintain a stable assemblage of several different genomes during the life cycle, but thi…

Expression profiling of up-regulated plant and fungal genes in early and late stages of Medicago truncatula - Glomus mosseae interactions

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Plants and Arbuscular Mycorrhizal Fungi: Cues and Communication in the Early Steps of Symbiotic Interactions

Abstract The ubiquitous nature of arbuscular mycorrhiza (AM) pleads for common molecular and genetic determinants across different plant taxa. The cellular processes determining compatibility in early interactions prior to and during cell contact between arbuscular mycorrhizal fungi and plant roots are starting to be unraveled. The root epidermis is an active checkpoint where signal exchanges and control over root colonization occur. Root‐secreted flavonoids, flavonols, and strigolactones can act as rhizosphere signals in stimulating presymbiotic fungal growth, although their mechanism of action on the fungal cell is as yet unknown. Likewise, fungal signals (Myc factors) activate early plan…

La tolérance au cadmium conférée par la symbiose endomycorhizienne s’accompagne de remaniements protéiques dans les organes aériens

Ultrastructural and cell wall modifications during infection of Eucalyptus viminalis roots by a pathogenic Fusarium oxysporum strain

Fusarium species are soil-borne fungal pathogens that produce a variety of disease symptoms when attacking crop plants. The mode of root colonization of Eucalyptus viminalis seedlings by a pathogenic F. oxyporum strain (Foeu1) at the ultrastructural level and changes in cell wall pectin during host pathogen interactions are described. Root systems of E. viminalis plants were inoculated with F. oxysporum in an in vitro model system. Hyphae of F. oxysporum adhered to the outer epidermal cell walls through fibrillar material, and after penetration they spread into the internal tissues. They developed intercellularly and intracellularly in the root cortex and invaded vascular tissues. Papillae …

Les mycorhizes éricoïdes : état de l'art et application

Signposting compatibility events initiating the mycorrhizal route

International audience

Molecular characterization and gene analysis of arbuscular mycorrhizal fungi

International audience

Les mycorhizes, le sol et le développement végétal

International audience

Monitoring fluctuations of an arbuscular mycorrhizal fungal community in plants roots and soil

International audience

Une approche rapide pour le suivi de la colonisation mycorhizienne à arbuscules des plantes en agriculture

National audience

Gènes activés lors de l'interaction racine / Glomus mosseae chez Medicago truncatula

National audience

Recherche de gènes codant des facteurs de transcription fongiques impliqués dans l’établissement de la symbiose mycorhizienne à arbuscules

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Cell interactions between a nonpathogenic Fusarium oxysporum strain and root tissues of Eucalyptus viminalis

Nonpathogenic isolates of Fusarium oxysporum can be successful antagonists of pathogenic forms of the same fungal species that commonly attacks crop plants. The characteristics that distinguish nonpathogenic from pathogenic forms are not well understood. In this study, the mode of root colonization of Eucalyptus viminalis seedlings by a nonpathogenic F. oxysporum strain is described at the ultrastructural level. Root systems of E. viminalis plants were inoculated with nonpathogenic F. oxysporum strain Fo47 in an in vitro model system. Changes in the occurrence of nonesterified and methyl-esterified pectins in colonized E. viminalis roots were evaluated by in situ immunolabeling using two mo…

Arbuscular mycorrhizal fungi, partners of the rhizostabilization proccess of an orphan mining site

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Vers la définition d’un programme symbiotique régissant les interactions mycorhiziennes

Arbuscular mycorrhizal fungi, partners of the rhizostabilization process of an orphan mining site

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Establishment of Petunia hybrida as model for studying mycorrhiza-induced resistance

Root pathogens play an important economical role in the production of vegetable and ornamental plants. They cause high losses especially in green house production and are difficult to combat by conventional methods, because the use of pesticides in soils or substrates is limited. The application of arbuscular mycorrhiza could be an alternative as mycorrhizal plants generally showed higher resistance against various soil-borne pathogenic fungi. The success of the inoculation is, however, not predictable and mechanisms behind the protective effects are largely unknown. The ornamental crop Petunia hybrida is among other solanaceous plants confronted with attack by root pathogens and was theref…

Identification of genes activated during arbuscular mycorrhiza interactions by suppressive substractive hybridisation and cloning of differential expresed cDNA

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Base composition of DNA from glomalean fungi: high amounts of methylated cytosine.

Glomales (Zygomycetes) are obligate fungal symbionts of roots of land plants and form arbuscular mycorrhiza. Sporal DNA of 10 isolates belonging to nine species was purified and the base composition was determined by RP-HPLC. Base composition fell in a narrow range between 30 and 35% G + C. A high amount of methylated cytosine (mC) accounting for 2-4% of the total nucleotides was found in all taxa. The DNA melting profile was defined for Scutellospora castanea. It corresponded to 32% G + C, and the shape of the denaturation curve suggested a heterogeneity in the GC content within the fungal genome. Knowledge of GC contents and variations between taxa are essential for evaluating nuclear DNA…

Tolérance au cadmium et mécanismes de détoxification chez le pois mycorhizé

National audience

Fungal genes related to calcium homeostasis and signalling are upregulated in symbiotic arbuscular mycorrhiza interactions

Fluctuations in intracellular calcium levels generate signalling events and regulate different cellular processes. Whilst the implication of Ca2+ in plant responses during arbuscular mycorrhiza (AM) interactions is well documented, nothing is known about the regulation or role of this secondary messenger in the fungal symbiont. The spatio-temporal expression pattern of putatively Ca2+-related genes of Glomus intraradices BEG141 encoding five proteins involved in membrane transport and one nuclear protein kinase, was investigated during the AM symbiosis. Expression profiles related to successful colonization of host roots were observed in interactions of G. intraradices with roots of wild-ty…

Mycorrhiza-related chitinase and chitosanase activity isoforms in Medicago truncatula Gaertn

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Cadmium accumulation and buffering of cadmium-induced stress by arbuscular mycorrhiza in three Pisum sativum L. genotypes

The role of arbuscular mycorrhiza in reducing Cd stress was investigated in three genotypes of Pisum sativum L. (cv. Frisson, VIR4788, VIR7128), grown in soil/sand pot cultures in the presence and absence of 2-3 mg kg(-1) bioavailable Cd, and inoculated or not with the arbuscular mycorrhizal fungus Glomus intraradices. Shoot, root and pod biomass were decreased by Cd in non-mycorrhizal plants. The presence of mycorrhiza attenuated the negative effect of Cd so that shoot biomass and activity of photosystem II, based on chlorophyll a fluorescence, were not significantly different between mycorrhizal plants growing in the presence or absence of the heavy metal (HM). Total P concentrations were…

Structural and functional genomics of symbiotic arbuscular mycorrhizal fungi.

The absorbing organs (roots, rhizomes) of nearly all terrestrial plant families host an intimate symbiotic association, called a mycorrhiza, with specialized functional groups of soil fungi. The most common type of root symbiosis is the arbuscular mycorrhiza where soil fungi interact with a tremendous diversity of plant species, including many forest trees and agricultural, horticultural, and fruit crops (Gianinazzi et al., 2002). The fungi involved are very ancient microorganisms compared to other true fungi. Fossil data and molecular phylogenetic analyses indicate that their origin dates back to the Ordovician-Devonian era some 460 to 400 million years ago (Remy et al., 1994; Redecker et …

Rôle du facteur de transcription fongique GintSTE dans l’établissement de la symbiose mycorhizienne à arbuscules

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La protéomique comme moyen d'identification de protéines induites par le cadmium et différenciellement régulées dans les racines de pois colonisées par un champignon mycorhizogène à arbuscules

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Impact of the growth of different maize genotypes on arbuscular mycorrhizal fungi

International audience

Arbuscular mycorrhiza induced ATPases and membrane nutrient transport mechanisms

The evolutionary success of arbuscular mycorrhizal (AM) symbiosis reflects the unique combination of a superior biotrophic mode of fungal carbon acquisition and the ability of the living plant to absorb nutrients, especially phosphorus, from the fungal partner (Jakobsen 1999). This mutualistic way of life must require controlled expression of a large set of membrane transport systems active in phosphate uptake from the soil by the extraradical hyphae, its transfer to the host plant across a symbiotic interface, and coupled to transport of photosynthates in the opposite direction. The implied membrane transporters are therefore integral systems in the functioning of the symbiosis. Very littl…

Morphogenetic events in interactions between arbuscular mycorrhizal symbionts

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Getting to the symbiotic proteome of Medicago truncatula

A simple and rapid method for collecting glomales spores from soil

International audience

25S rDNA-based molecular monitoring of glomalean fungi in sewage sludge-treated field plots

Recycling of sewage wastes in agriculture is likely to affect the biological activity of soils through contamination of ecosystems by pathogens and metallic or organic micropollutants. The impact of sewage sludge spreading under field conditions on arbuscular mycorrhiza (AM) formation by a community of glomalean fungi was evaluated using a nested polymerase chain reaction (PCR) and discriminating primers based on 25S rDNA polymorphisms to detect different fungal species within root systems. Medicago truncatula was grown in soil of field plots amended or not with a composted sewage sludge, spiked or not with organic or metallic micropollutants. Overall AM development in roots decreased with …

A proteomic approach to study the effects of two polycyclic aromatic hydrocarbons on arbuscular mycorrhiza of Cichorium intybus roots in gnotobiotic conditions

Isolation of pea (Pisum sativum) mutants impaired in arbuscular mycorrhiza development, using a direct screening

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Gene expression linked to symbiosis resistance in pea mutants

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« PPHD » : A Platform For High Throughput Phenotyping of Plant/Plant and Plant/Microorganisms Interactions

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The use of genomic repeated sequences to characterize arbuscular mycorrhizal fungi

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EST sequencing for fungal genes expressed in the arbuscular symbiosis

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Gene responses to non rhizobial beneficial microbe interactions in legumes

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Signalling between arbuscular mycorrhizal fungi and plants: Identification of a gene expressed during early interactions by differential RNA display analysis

Although there is evidence for an interplay of signalling/recognition events at different stages during plant/fungal interactions in arbuscular mycorrhiza, the nature of signalling molecules and signal perception/transduction processes are so far unknown. Virtually nothing is known of molecular interactions during initial contact between arbuscular mycorrhizal symbionts, but plant mutants which limit fungal development to these first steps (myc-1) provide proof of the involvement of plant genes. One such pea mutant (P2) has been used to investigate gene expression during early plant-fungal interactions by differential RNA display. Partial transcriptome analysis has indicated frequent simila…

Functional genomics of arbuscular mycorrhiza : decoding the symbiotic cell programme

More extensive insight into plant genes involved in the symbiotic programme of arbuscular mycorrhiza is presently being achieved by global approaches that aim to discover novel genes or subsets of genes that are essential to cell programmes in the different steps of plant–fungal interactions. The strategy of functional genomics based on large-scale differential RNA expression analyses (differential-display reverse transcriptase - PCR), electronic Northerns, suppressive subtractive hybridization, DNA chips) is presented, with a focus on arbuscular mycorrhiza in Pisum sativum and Medicago truncatula. The most recent knowledge about gene networks that are modulated in roots during arbuscular …

Mtha1, a plasma membrane H+ - ATPase gene from Medicago truncatula, shows arbuscule-specific induced expression in mycorrhizal tissue

International audience

Spatial monitoring of gene activity in extraradical and intraradical developmental stages of arbuscular mycorrhizal fungi by direct fluorescent in situ RT-PCR

International audience; Gene expression profiling based on tissue extracts gives only limited information about genes associated with complex developmental processes such as those implicated in fungal interactions with plant roots during arbuscular mycorrhiza development and function. To overcome this drawback, a direct fluorescent in situ RT-PCR methodology was developed for spatial mapping of gene expression in different presymbiotic and symbiotic structures of an arbuscular mycorrhizal fungus. Transcript detection was optimized by targeting the LSU rRNA gene of Glomus intraradices and monitoring expression of a stearoyl-CoA-desaturase gene that is consistently expressed at high levels in…

Pea genes modulate symbiosis-associated fungal and plant molecular responses during late stages of the arbuscular mycorrhizal symbiosis

International audience

Changes in the glomeromycota community in soils treated with a mix of pesticides

International audience

Identification of plant and fungal genes involved in the late stages of arbuscular mycorrhizas development

International audience

Fungal protein accumulation in the extra - radical phase of arbuscular mycorrhiza: a shotgun proteomic picture

Hydrolytic enzyme activity of Paenibacillus sp. strain B2 and effects of the antagonistic bacterium on cell integrity of two soil-borne pathogenic fungi

Paenibacillus sp. strain B2, isolated from the mycorrhizosphere of Sorghum bicolor and having an antagonistic activity towards soil-borne fungal pathogens, possessed extracellular cellulolytic, proteolytic, chitinolytic and pectinolytic enzyme activities. The eventual role of these lytic enzymes in cellular interactions between Paenibacillus sp. strain B2 and Phytophthora parasitica and Fusariumoxysporum was investigated by electron microscopy and molecular cytology. Electron microscopic observations showed that the presence of Paenibacillus sp. strain B2 resulted in disorganisation of cell walls and/or cell contents of P. parasitica and F. oxysporum. However, when P. parasitica was treated…

Un répertoire GeLC - MS/MS des protéines extra - radiculaires de Glomus intraradices

Genomics of arbuscular mycorrhizal fungi

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Regulation of gene expression during endomycorrhizal infection

International audience

Effets de l'endomycorhization sur la compétition de l'oignon vis-à-vis de quelques espèces adventices

National audience

Phosphorus tolerance of an hypermycorrhizal mutant of Medicago truncatula

International audience

Developmental regulated fungal gene expression in mycorrhizal interactions with host and non host Medicago truncatula

International audience

Evaluation moléculaire in planta de la diversité des champignons mycorhizogènes dans des champs amendés avec des boues d'épuration

National audience

Biodiversity and characterization of arbuscular mycorrhizal fungi at the molecular level

Biodiversity within a biological group provides the basis for distinguishing members into genera and species according to taxonomic criteria, and between individuals within a species depending on more detailed differences at the genetic level. Diversity between species occurs after a genetic barrier has been created either by a geographic or genetic impedance of gene flow. Divergence can continue by nucleotide substitutions and by mutations in a broader sense (deletions, translocations, duplications), and resulting diversity can be evaluated at the molecular level and used as a phylogenetic character. Diversity at the subspecies level is a function of both mutation rates and gene flow betwe…

Corrigendum to “Spatial monitoring of gene activity in extraradical and intraradical developmental stages of arbuscular mycorrhizal fungi by direct fluorescent in situ RT-PCR” [Fungal Genet. Biol. 45 (2008) 1155–1165]

Targeted proteomics to identify cadmium-induced protein modifications in Glomus mosseae-inoculated pea roots

International audience

Expression of genes encoding membrane intrinsic proteins (MIP) in arbuscular mycorrhizal parsley, tobacco and fababean

International audience